Astronomers have discovered what they believe is the first
direct evidence of the astonishing expansion of the universe in the
instant following the Big Bang -- the scientific explanation for the
birth of the universe some 13.8 billion years ago.
Scientists believe that the universe exploded from a tiny speck and
hurled itself out in all directions in the fraction of a second that
followed, beginning just 10 to the minus 35 seconds (roughly one
trillionth of a trillionth of a trillionth of a second) after the
universe's birth. Matter ultimately coalesced hundreds of millions of
years later into planets, stars, and ultimately us.
And like ripples from a ball kicked into a pond, that Big Bang-fueled
expansion caused ripples in the ancient light from that event, light
which remains imprinted in the skies in a leftover glow called the
cosmic microwave background.
Scientists still don’t know who kicked the ball.
But if confirmed, the newfound ripples would be amazing proof of what
has long been mere theory about what happened in those first millionths
of a second.
'[It's] a direct image of gravitational waves across the entire sky, showing us the early universe.'
- John Kovac, of the Harvard-Smithsonian Center for Astrophysics
“The implications for this detection stagger the mind,” said Jamie
Bock, professor of physics at Caltech, laboratory senior research
scientist at the Jet Propulsion Laboratory (JPL) and project co-leader.
“We are measuring a signal that comes from the dawn of time.”
"It would be the most important discovery since the discovery, I
think, that the expansion of the universe is accelerating," Harvard
astronomer Avi Loeb, who is not a member of the study team, told
Space.com. He compared the finding to a 1998 observation that opened the
window on mysterious dark energy and won three researchers the 2011
Nobel Prize in physics.
The groundbreaking results came from observations by BICEP2, a
telescope at the South Pole, of the cosmic microwave background -- a
faint glow left over from the Big Bang.
Beginning a fraction of a fraction of a second after the universe's
birth, according to the current theory, space-time expanded incredibly
rapidly, ballooning outward faster than the speed of light. The
afterglow from that expansion is called the cosmic microwave background,
and tiny fluctuations in it provide clues to conditions in the early
universe.
For example, small differences in temperature across the sky show
where parts of the universe were denser, eventually condensing into
galaxies and galactic clusters.
Since the cosmic microwave background is a form of light, it exhibits
all the properties of light, including polarization. On Earth, sunlight
is scattered by the atmosphere and becomes polarized, which is why
polarized sunglasses help reduce glare. In space, the cosmic microwave
background was scattered by atoms and electrons and became polarized
too.
“Our team hunted for a special type of polarization called ‘B-modes,’
which represents a twisting or ‘curl’ pattern in the polarized
orientations of the ancient light,” said Bock.
The team presented their work at a press conference Monda at Harvard
-- the discovery of that characteristic pattern of polarization in the
skies, which they called proof of the gravitational waves across the
primordial sky.
“This work offers new insights into some of our most basic questions:
Why do we exist? How did the universe begin? These results are not only
a smoking gun for inflation, they also tell us when inflation took
place and how powerful the process was,” Harvard theorist Avi Loeb said.
data delayed 20 minutes.
